Let's start by drawing a diagram corresponding to the situation. Notice that the sushi roll can be modeled by a circle, with the chopsticks being .

The diameter of the circle is then $3.5$ cm, the length of arc $BC$ is $4.7$ cm, and we are interested in the measure of angle $∠A.$ To find this, we'll first need the $BC,$ which we can find by the . The circumference is
$πd=π⋅3.5≈11.0cm.$
We can now calculate the arc measure.

$circumferencearc length =360_{∘}arc measure $

$11.04.7 =360_{∘}arc measure $

$11.04.7 ⋅360_{∘}=arc measure$

$153.81818…_{∘}=arc measure$

$154_{∘}≈arc measure$

$arc measure≈154_{∘}$

We now know that the measure of arc $BC$ is $154_{∘}.$ As $ABOC$ is a quadrilateral, it has the interior angle sum $360_{∘}.$ With $m∠B$ and $m∠C$ being $90_{∘},$ the sum of $m∠A$ and $m∠O$ must then be $180_{∘}.$

$m∠A+m∠O=180_{∘}$

$m∠A+154_{∘}=180_{∘}$

$m∠A=26_{∘}$

The measure of the circumscribed angle is $26_{∘}.$